Chemically amplified resist composition and manufacturing method of semiconductor integrated circuit device with such chemically amplified resist composition

ABSTRACT

With the damascene process in which an interconnection is formed using a conventional chemically amplified positive photoresist composition, there arises a problem that the photoresist within the via hole (as well as in its vicinity) may remain even after the exposure and the development are carried out. The present invention relates to a chemically amplified resist composition comprising, at least, a photo acid generator, a quencher and a salt having a buffering function for an acid which is generated from the acid generator by irradiation, wherein the salt having the buffering function for the acid generated from the acid generator is a salt derived from a long chain alkylbenzenesulfonic acid or a long chain alkoxybenzenesulfonic acid and an organic amine that is a basic compound.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chemically amplified resistcomposition and a manufacturing method of a semiconductor integratedcircuit device wherein such a chemically amplified resist composition isutilized.

2. Description of the Related Art

The recent advance in the degree of integration in the semiconductorintegrated circuit has put the ULSI (Ultra Large-Scaled Integratedcircuit) into practical use. The technology to produce the ULSI has beenattained through the progress in the miniaturization of conductiveinterconnections, electrodes and the like, and the minimum patterncurrently in practical use is in the submicron range of 0.14 μm, whilethe minimum pattern aimed to attain at the moment is of 0.08 μm.Accompanying the miniaturization, the change in the light beam used forthe exposure in the resist pattern formation has been taking place, fromthe ultraviolet rays conventionally utilized to the radioactive rayssuch as far-ultraviolet rays, electron rays and X-rays, with itswavelength shifting to a shorter region.

The chemically amplified resist is a very resist material that can standthe use under these shorter wavelengths and is used as such.

With the chemically amplified photoresist, its irradiated section ismade soluble in an alkaline developer solution through a chemicalreaction that is catalyzed by an acid generated from an acid generatorby irradiation. Some chemically amplified photoresists provide positivepatterns and the others, negative patterns.

In the case of the chemically amplified positive resist, the resistwherein a photo acid generator (PAG) is mixed into polymers is used, andthe exposure (irradiation) of the chemically amplified positive resistsets off chain-reacting elimination reactions or hydrolytic reactions inthe polymers, with a Brensted acid generated from the photo acidgenerator by exposure acting as a catalyst, forming hydrophilic groupsin the polymers and rendering the exposed section soluble in thealkaline developer solution, and thereby a positive resist pattern isformed.

In the case of the chemically amplified negative resist, the resistwherein a cross-linking agent and a photo acid generator are added andmixed into polymers which are soluble in the developer solution is used.With a Brensted acid generated from the photo acid generator by exposureacting as a catalyst, the exposure sets off chain-reacting cross-linkingreactions in the polymers, making them to have larger molecular weights,and, at the same time, the polar groups thereof nonpolar bycross-linking so that the exposed sections are made insoluble in thedeveloper solution, and thereby a negative resist pattern is formed.

In the case of the chemically amplified positive resist, however, thephoto acid generator itself may be dissociated by exposure and the acidconcentration in the vicinity of the resist surface is increased, givingrise to a problem that the pattern takes the form of a taper.

Meanwhile, in the case of the chemically amplified negative resist, thephoto acid generator itself may be dissociated by exposure and the acidconcentration in the vicinity of the resist surface is increased, givingrise to a problem that the top section of the pattern becomesoverhanging in shape.

To overcome such problems, it has been known that the basic compound canbe added into the chemically amplified resist with the object ofcontrolling acid diffusion. Since the added basic compound is consideredto quench the acid which is generated from the photo acid generator byirradiation, it is generally called a quencher. The addition of thequencher suppresses the formation of the surface layer of low solubilityand leads to improvements in various aspects such as the sensitivity,the resolution, the pattern shape and the process stability.

Along with the progress in the miniaturization, a variety of compoundsare even now being developed as a quencher and Japanese PatentApplication Laid-open No. 100400/2001 and WO No. 004706/2001 disclosesome of them.

In Japanese Patent Application Laid-open No. 100400/2001, there isselected a compound with an annular frame containing at least onenitrogen atom, which can be decomposed by an acid generated from a photoacid generator by exposure to form an acid weaker than the originalacid. Further, in WO No. 004706/2001, there is given an amine derivativehaving a specific basicity as a quencher.

Now, referring to the drawings, a method of manufacturing asemiconductor integrated circuit device wherein an ordinal trenchinterconnection is utilized is described below.

FIG. 2 shows one example of a conventional manufacturing method of a viahole first type dual damascene interconnection.

First, a coating of a first anti-reflection film (not shown in thedrawings) is applied onto the entire surface of a substrate wherein afirst etching barrier film 7, a first interlayer insulating film 6, asecond etching barrier film 5, a second interlayer insulating film (alow-dielectric-constant film) 4 and a cap film (an insulating film) 3are formed on a Cu lower layer interconnection layer 8, in this order,from the side of the substrate, and a first photoresist pattern (for viahole formation) is formed on the surface of the first anti-reflectionfilm. Subsequently, using this first photoresist pattern as an etchingmask, the first anti-reflection film, the cap film 3, the secondinterlayer insulating film 4, the second etching barrier film 5 and thefirst interlayer insulating film 6 are selectively etched in successiontill the first etching barrier film 7 is exposed, and thereby a via hole21 is formed (See FIG. 2( a)).

For the damascene interconnection structure, because Cu is utilized asthe interconnection metal, the acid cleaning cannot be employed afteretching of the via hole on the grounds that this cleaning, through thevia hole which has been just made open, may cause oxidation of the metalused in the interconnection. Yet, ashing alone cannot remove etchingresidues thoroughly. The organic peeling-off is, therefore. carried outafter the step of ashing, using an organic peeling agent.

Next, after the first anti-reflection film and the first photoresistpattern are removed with ashing and the use of the organic peeling agent(See FIG. 2( a)), a second anti-reflection film 2 is formed over theentire surface of the substrate (in such a way that the via hole 21 maynot be filled up completely) (See FIG. 2( b)) and a coating of aphotoresist 1 is applied onto the surface of the anti-reflection film 2(See FIG. 2( c)). With exposure being applied onto the coating of thephotoresist, a second photoresist pattern 1 (for interconnection trenchformation) is formed (See FIG. 2( d)) and, then, using this as anetching mask, the second anti-reflection film 2, the cap film 3 and thesecond interlayer insulating film 4 are selectively etched in successiontill the second etching barrier film 5 is exposed (See FIGS. 2( e) and(f)), and thereby an interconnection trench 22 is formed.

Next, after the second anti-reflection film 2 and the second photoresistpattern 1 are peeled off or removed with ashing and the use of theorganic peeling agent, the exposed first etching barrier film 7 isetched by the etch back method till the Cu lower layer interconnectionlayer 8 is exposed (See FIG. 2( g)). Next, following the cleaning of thesubstrate where a part of the Cu lower layer interconnection layer 8 isexposed a seed film and a metal barrier film are formed on thesubstrate, and thereafter a Cu plating film 9 is grown so as to fill upthe via hole and the interconnection trench. After that, carrying outthe CMP (Chemical Mechanical Polishing), the Cu plating film 9 and thecap film 3 are planarized (till the cap film 3 becomes almost completelyremoved) (See FIG. 2( h)). A dual damascene interconnection 9 that iselectrically connected with the Cu lower layer interconnection layer 8is thereby formed.

However, when the second photoresist pattern 1 is formed using aconventional chemically amplified positive photoresist composition,there arises a problem that the photoresist within the via hole 21 (aswell as in its vicinity) may remain even after the exposure and thedevelopment are carried out.

To the positive resist, this phenomenon corresponds to the lowering ofthe sensitivity of the photoresist in part.

The cause to bring about such a problem is, in the present inventors'view, as follows. When application of coatings of an anti-reflectionfilm and a chemically amplified photoresist composition and the exposurethereto are made without any pretreatment (heat treatment, UV treatment.oxygen plasma treatment or such), contaminants such as basic compoundsand the moisture which are attached onto or seeped into the substratesurface (such as the wall surface of the via hole in the interlayerinsulating film) may pass through the anti-reflection film and permeateinto the photoresist in baking (a pre-bake: for removing the solvent) ofthe anti-reflection film and the photoresist.

In other words, because a deep opening and a deep trench are formed inthe via hole first type dual damascene method, residues formed at thetime of dry etching cannot be removed by ordinary cleaning methods.Therefore, an alkaline organic peeling agent including an organic amineis employed to accomplish thorough removal.

The contaminants such as basic compounds (amine components) contained inthis organic peeling agent, the moisture and floating basic substancesin the air become concentrated by attaching onto or seeping into thewall surface (interlayer insulating film) of the via hole. After that,when coatings of an anti-reflection film and a photoresist (a chemicallyamplified positive photoresist composition) for the interconnectiontrench are applied onto the substrate surface including the wall surfaceof the via hole, and pre-bake is conducted, the contaminants whichbecome concentrated by attaching onto or seeping into the wall surfaceof the via hole permeate into the photoresist from the wall surface ofthe via hole, passing through the anti-reflection film. On irradiation,the permeated contaminants (such as amine components) neutralize thecatalyst acid (H+) generated by photolysis of the photo acid generatorcontained in the photoresist (chemically amplified positivephotoresist). The neutralization of the catalyst acid with thesecontaminants deactivates (becomes short of) the acidic catalysts in thephotoresist (which is called the poisoning).

The photoresist in the region where the acidic catalysts are deactivatedbecomes incapable of undergoing a change (polarity change) to convertinto a substance soluble in the developer solution. (For instance, aprotecting group such as an acetal group becomes deblocked so that achain reaction to form a hydroxyl group becomes difficult to takeplace). The photoresist in the region (within the via hole or in itsvicinity) where the conversion into a substance soluble to the developersolution does not occur remains without dissolving. This makes theresist pattern within the via hole or in its vicinity have defectiveresolution.

Further, the experiments conducted by the present inventors showed that,with conventional chemically amplified resists, if the condition allowedthe poisoning to occur, the development performed for 30 seconds couldprovide good resist patterns in the absence of the via hole but theresist pattern formed thereby around the via holes had faulty resolutiondue to severe poisoning. Although the resistance against poisoning couldbe raised by extending the development time period to 60 seconds, theresulting resolution remained insufficient.

Further, the experiments by the present inventors revealed such aproblem (faulty resolution) became more marked if, in place ofconventional silicon oxide films, low-dielectric-constant insulatingfilms (Low-k films; for example, the dielectric constant <3.0) wereutilized for the first interlayer insulating film 4 and the secondinterlayer insulating film 6. That is, when low-dielectric-constantinsulating films were used, there arose a problem that the region wherethe photoresist remained without dissolving in the developer solution(the photoresist remained unresolved even though having subjected to theexposure) expanded.

This sort of the problem is considered by the present inventors toresult from a fact that the low-dielectric-constant films (Low-k films)are often porous films whose molecular structure have spatial gaps andmoreover, because these gaps (fine holes) tend to increase for thesubstances with lower dielectric constants, more contaminants becomeliable to attach onto (adsorb) or seeped into for thelow-dielectric-constant films than for the ordinary interlayerinsulating films (SiO2). As a result, the amount of contaminants topermeate into the photoresist from the low-dielectric-constant filmbecomes greater than that from the silicon oxide film and the regionwhere the resist pattern has poor resolution expands.

The remaining photoresist of this sort covers circumference section ofthe via hole on the surface of the cap film 3, and, when theinterconnection trench 22 is formed by etching, the remainingphotoresist becomes halo-like on the cap film 3 so that a taperingcylindrical projection 10 made of the cap film 3 or the secondinterlayer insulating film 4 is formed in peripheral region of the viahole (See FIG. 2( g)). In the case that the low-dielectric-constantfilms (Low-k films) are employed for the interlayer insulating films,the projection 10 becomes larger. If formation of the Cu dual damasceneinterconnection 9 is carried out, while such a projection 10 remains,the presence of the projection 10 brings about separation or faultyconnection between the via plug section and the interconnection sectionin the dual damascene interconnection 9 and, thus, results inunsatisfactory electrical connection between the via plug section andthe interconnection section in the dual damascene interconnection 9 (SeeFIG. 2( h)). Accordingly, the reliability of the semiconductor devicedeteriorates.

SUMMARY OF THE INVENTION

The present invention relates to a chemically amplified resistcomposition comprising, at least, a photo acid generator, a quencher anda salt having a buffering function for an acid which is generated fromsaid acid generator by irradiation, wherein the salt having thebuffering function for the acid generated from the acid generator isspecifically a salt derived from a long chain alkylbenzenesulfonic acidor a long chain alkoxybenzenesulfonic acid and an organic amine that isa basic compound, being expressed by the following Formulae (1), (1a) or(1b).

(In the Formula, R each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. n is 0 or 1and m is an integer of 3 to 23. k is an integer of 0 to 4. Examples of Binclude primary, secondary and tertiary aliphatic amines, mixed amines,aromatic amines, heterocyclic amines, nitrogen-containing compounds witha carboxy group, nitrogen-containing compounds with a sulfonyl group,nitrogen-containing compounds with a hydroxy group, nitrogen-containingcompounds with a hydroxyphenyl group, alcoholic nitrogen-containingcompounds, nitrogen-containing compounds with a cyano group, amidederivatives and imide derivatives. I is an integer of 1 to 3.)

(In the Formula, Rs each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. N is 0 or1, and k is an integer of 0 to 4. Mm is an integer of 3 to 11 and p isan integer of 1 to 3. Side chains X can be identical or different andeach expressed by one of the following general Formulae (X)-1 to (X)-3.Side chains Y can be identical or different, each representing ahydrogen atom or a straight, branched or cyclic alkyl group containingfrom 1 to 20 carbons, which may comprise an ether group or a hydroxylgroup. Further, Xs may combine with each other to form a ring. Herein,R³⁰⁰, R³⁰² and R³⁰⁵ are each a straight or branched alkylene groupcontaining from 1 to 4 carbons, R³⁰¹ and R³⁰⁴ are each a hydrogen atomor a straight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether groups,ester groups and/or lactone rings. R³⁰³ is a straight or branchedsingle-bond alkylene group containing from 1 to 4 carbons, and R³⁰⁶ is astraight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether groups,ester groups and/or lactone rings.)

(In the Formula, Rs each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. n is 0 or1, and k is an integer of 0 to 4. A side chain X can be expressed by oneof the above-mentioned general Formulae (X)-1 to (X)-3. mm is an integerof 3 to 11 and R³⁰⁷ is a straight or branched alkylene group containingfrom 2 to 20 carbons, which may comprise one or more carbonyl groups,ether groups, ester groups and/or sulfides.)

In the present invention, by containing a salt having a bufferingfunction for an acid generated from an acid generator, excellent resistpatterns can be formed even on a substrate surface where an organicpeeling agent (poisoning substance) is attached or seeped withoutlowering the exposure sensitivity.

Further, with the buffering effect functioning, the influence thatfluctuations in exposure dose has over the acidity becomes smaller andless immediate so that the exposure dose margin for the resistincreases.

Further, when, using the chemically amplified resist, the resist patternis obtained by the photolithography, anomalous bodies tend to appear inthe resist and, thus, the resist storage temperature, time period inuse, temperature condition for the development and such must be keptunder strict control. In contrast with this, in the present invention,the very appearance of the anomalous bodies is lessened. The drop of theanomalous body appearance leads to an decrease in the number of defectscaused by anomalous bodies after the exposure and development of theresist are carried out and, therefore, the occurrence of the severanceof the interconnection and the faulty connection of the via plug isdiminished.

Further, when a basic substrate of TiN, SiN, SiCN, SiON or such is used,the resist pattern with a chemically amplified positive resist tends toshow long tails. Against this, too, the resist in the present inventionhas an effect of reducing this tailing phenomenon.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a series of schematic cross-sectional views illustrating thesteps of a manufacturing method of a semiconductor integrated circuitdevice wherein a chemically amplified positive resist composition of thepresent invention is used.

FIG. 2 is a series of schematic cross-sectional views illustrating thesteps of a manufacturing method of a semiconductor integrated circuitdevice wherein a conventional chemically amplified positive resistcomposition is used.

FIG. 3 is a pair of graphs showing results of the capillaryelectrophoresis method, identifying components attached onto thesubstrate of Example with Low-k films after the treatment with theorganic peeling agent.

FIG. 4 is a diagram showing the number of defects in the via hole LIS(line and space) pattern for various salts in the4-n-alkylphenylsulfonic acid tris(2-hydroxyethyl)amine system containingdifferent number of carbons in the acid part.

Numerical reference 1 indicates a photoresist film (resist pattern); 2,an anti-reflection film; 3, a cap film; 4, an interlayer insulatingfilm; 5, an etching barrier film; 6, another interlayer insulating film;7, another etching barrier film; 8, a Cu lower layer interconnection; 9,a Cu plating layer; 10, a projection; 21, a via hole and 22, aninterconnection trench.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

The present inventors found that an acid which is generated from thephoto acid generator when the chemically amplified type resist issubjected to the exposure behaves, in the resist, as an acid with a lowdegree of dissociation, although it is regarded, in an aqueous solution,as a strong acid. As a result, an organic derivative acting as aquencher neutralized the acid generates from the photo acid generator inthe resist to form a salt containing a conjugate base for the acid. Ineffect, following the exposure, there is formed, in the resist, a systemof “a weak acid” and “a salt containing its conjugate base”, which hasthe buffering effect.

In consequence, the dissociation of the acid in the resist is controlledand even when impurities of basicity are seeped into the resist from theoutside, the basic substances are neutralized by the undissociated acidsabundantly present therein so that the change of concentration of thedissociated acid is well suppressed due to the buffering function.

In the conventional cases, only a quencher is added so that “the saltcontaining a conjugate base” must be formed by the neutralizing reactionbetween the quencher and the acid that is generated in the resist fromthe photo acid generator following the exposure.

This necessitates a great amounts of the acids to be generated with ahigh exposure dose and it was noticed that this is the very reason tolower the exposure sensitivity. In the present invention, together witha quencher, a salt containing a conjugate base with the bufferingfunction to control the change of the acid concentration or a salt withthe buffering function is contained in the resist and thereby achemically amplified type resist for which a rise in the exposure doseis unnecessary is provided.

The present invention can apply both a positive and a negativechemically amplified resist composition as long as a quencher iscontained therein.

EXAMPLES

Using a chemically amplified positive resist composition, a photoresistcomposition of the present Example is described below.

A chemically amplified positive resist composition comprises a baseresin, an acid generator, a quencher, a solvent and a salt which isadded to control the dissociation of the acid generated from the acidgenerator.

The base resin in the present Example is a resin where a part ofpolyhydroxystyrene is protected by an acid labile group (a protectinggroup; an acetal group) (mentioned below, See Formulae (2)) and thisresin having an acid functional group protected by an acid labile groupis either insoluble or difficult to be dissolved in an alkalinesolution, and becomes alkali-soluble when that acid labile group iseliminated therefrom. The weight average molecular weight (Mw) of thisbase resin is 10,500. The substitution ratio (the protection ratio) bythe acid labile group in this base resin is 30 mol % (phenol typehydroxy group 70 mol %). The polydispersity index (Mw/Mn) for this baseresin is 1.1 (Mn is the number average molecular weight). In addition topolyhydroxystyrene, the base resin can be a resin wherein a part ofphenol type hydroxy groups in polyhydroxystyrene derivative is protectedby an acid labile group. In this case, the weight average molecularweight of this base resin is preferably set 5,000 to 100,000. When it isless than 5,000, its film quality or resolution, may becomeunsatisfactory. On the other hand, when it exceeds 100,000, itsresolution power may become insufficient. For the acid labile group inthe base resin, one or more types of groups can be also selected fromthe group consisting of a group represented by Formula (3) shown below,a group represented by Formula (4) shown below, a tertiary alkyl groupcontaining from 4 to 20 carbons, a trialkylsilyl group whose alkylgroups each contain from 1 to 6 carbons and an oxoalkyl group containingfrom 4 to 20 carbons. The substitution ratio with the acid labile groupin the base resin is preferably 0 to 80 mol % and particularlypreferably 12 to 70 mol %. More detailed description for the base resincan be found in Paragraph [0046] to [0075] of Japanese PatentApplication Laid-open No. 84639/1999 and Paragraph [0011] to [0017] ofJapanese Patent Application Laid-open No. 194776/2001. Further, for thebase resin, what is called an ESCAP (Environmentally Stable ChemicallyAmplified Positive) type polymer (See Japanese Patent ApplicationLaid-open No. 139696/2001) which uses a copolymer made of hydroxystyreneand metacrylic acid esters can be employed but it was found that faultyresolution is more liable to occur than when an acetal protecting groupis used. On the other hand, for the purpose of giving a rectangular formand such, it was shown to be effective that a small amount of the ESCAPtype polymer is blended into the acetal-based polymer not so far as theresist resolution is worsened. Further, the base resin (polymermaterial) is not limited to the one used for the KrF excimer laser(wavelength: 248 nm) lithography, but it is considered that the polymermaterials suitable to the light sources used for other lithography suchas the i-line (wavelength: 365 nm) laser lithography, ArF (wavelength:193 nm) excimer laser lithography, the F2 excimer laser (wavelength: 157nm) lithography, the extreme ultraviolet (EUV, wavelength: 157 nm)lithography, the X-ray lithography (wavelength: 0.1-100 nm) and theelectron beam (1 KeV-300 KeV) lithography can be chosen to obtainsimilar effects.

As the acid generator PAGs 1 to 5 (See Formula 5 shown below) are usedin the present Example and its amount used (the total amount used) is 1to 9.6 parts by weight per 100 parts of the base resin by weight. Forthe acid generator, aside from the PAGs 1 to 5, there can be given oniumsalts, diazomethane derivatives, glyoxime derivatives, β-ketosulfonederivatives, disulfone derivatives, nitrobenzenesulfonate derivatives,sulfone acid ester derivatives and imidoylsulfonate derivatives.Further, its amount used is preferably 0.2 to 20 parts by weight andmore preferably 0.5 to 10 parts by weight per 100 parts of the baseresin by weight. When it is less than 0.2 parts by weight, the amount ofacid generation on the exposure may be very little and the resolution,low. On the other hand, when it exceeds 20 parts by weight, there may beoccasions the resist transmission drops and the resolution deterioratesconsiderably. More detailed description for the acid generator can befound in Paragraph [0076] to [0084] of Japanese Patent ApplicationLaid-open No. 84639/1999 and Paragraph [0018] to [0028] of JapanesePatent Application Laid-open No. 194776/2001.

As the basic compound (quencher), one or two types of triethanolamine,tri-n-butylamine and 2-butoxypyridine are used in the present Exampleand its amount of addition is, in the present Example, 10 to 42 mmol ofthe basic compound per 100 g of the base resin (the unit is,hereinafter, set mmol/poly-1000 g). For the basic compound (quencher),in addition to the above substances, any substance of primary, secondaryand tertiary aliphatic amines, mixed amines, aromatic amines,heterocyclic amines, nitrogen-containing compounds with a carboxy group,nitrogen-containing compounds with a sulfonyl group, nitrogen-containingcompounds with a hydroxy group, nitrogen-containing compounds with ahydroxyphenyl group, alcoholic nitrogen-containing compounds, amidederivatives and imide derivatives, all of which have been conventionallyused, can be employed. Further, the amount of addition for the basiccompound (quencher) is preferably 1 to 100 mmol/poly-1000 g andparticularly preferably 2 to 50 mmol/poly-1000 g. When it exceeds 1mmol/poly-1000 g, the acid generates sufficiently on the exposure andthe sensitivity is not lowered. When it is less than 6 mmol/poly-1000 g,the sensitivity is not greater than 200 mJ/cm2 and the throughput is notlowered. More detailed description for the type of the basic compoundsand such can be found in Paragraph [0027] to [0043] of Japanese PatentApplication Laid-open No. 84639/1999 and Paragraph [0008] to [0009] andParagraph [0030] to [0033] of Japanese Patent Application Laid-open No.194776/2001.

For the organic solvent, one or two types of propylene glycol monomethylether acetate (PGMEA) and ethyl lactate (EL) are used in the presentExample and its amount used in the present Example is 600 parts of thesolvent by weight per 100 parts of the base resin by weight. As for theorganic solvent, in addition to the above solvents, any solvent intowhich the base resin, the acid generator and such are soluble can beemployed, and these examples include, but not limited to, ketones,alcohols, ethers and esters. Each type of these can be used alone or amixture of two or more types of these may be used. Further, the amountused for the organic solvent is preferably 100 to 5000 parts of thesolvent by weight and more preferably 300 to 2000 parts of the solventby weight per 100 parts of the base resin by weight. As mentioned inmore detailed description for the organic solvent in Paragraph [0044] to[0045] of Japanese Patent Application Laid-open No. 84639/1999 andParagraph [0010] of Japanese Patent Application Laid-open No.194776/2001, any organic solvent capable of dissolving an acidgenerator, a base resin and such can be employed. Examples of such anorganic solvent include, but not limited to, ketones such ascyclohexanone and methyl-2-n-amyl ketone; alcohols such as3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol and1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether,ethylene glycol monomethyl ether, propylene glycol monoethyl ether,ethylene glycol monoethyl ether, propylene glycol dimethyl ether anddiethylene glycol dimethyl ethers; and esters such as propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate,ethyl lactate, ethyl pyruvate, butyl acetate, methyl3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate,tert-butyl propionate and propylene glycol mono-tert-butyl etheracetate, which can be used alone or in combination of two or more typesthereof. Among these organic solvents preferably used are diethyleneglycol dimethyl ether, 1-ethoxy-2-propanol and ethyl lactate whichexhibit the highest ability of dissolving an acid generator in a resistcomposition, and propylene glycol monomethyl ether acetate which is asafe solvent, as well as mixtures thereof.

For a salt with the buffering function to regulate the concentrationchange of the acid which is generated from the acid generator, a saltderived from an organic sulfonic acid derivative and an organic aminethat is a basic compound is chosen. It was demonstrated that the resistmaterial containing the salt has excellent storage stability and coatingquality and, with this material, even a considerably long PED (PostExposure Delay) causes only a small line width variation and little formdeterioration, and besides the resist formed on a basic substrate ofTiN, SiN, SiCN, SiON or such, hardly tails or very few anomalous bodiesare found after the coating, after the development and after thepeeling-off. Moreover, the use of this material was shown to produceexcellent pattern profile shape after the development, providing highresolution suitable to the microfabrication and, thus, particularlyeffective in the deep UV lithography.

Specifically, a salt derived from a long chain alkylbenzenesulfonic acidor a long chain alkoxybenzenesulfonic acid, expressed by the followinggeneral Formula (1), (1-a) or (1-b), was found to be well suited.

(In the Formula, R each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. N is 0 or1, and m is an integer of 3 to 23. k is an integer of 0 to 4. Examplesof B include primary, secondary and tertiary aliphatic amines, mixedamines, aromatic amines, heterocyclic amines, nitrogen-containingcompounds with a carboxy group, nitrogen-containing compounds with asulfonyl group, nitrogen-containing compounds with a hydroxy group,nitrogen-containing compounds with a hydroxyphenyl group, alcoholicnitrogen-containing compounds, nitrogen-containing compounds with acyano group, amide derivatives and imide derivatives. I is an integer of1 to 3.)

(in the Formula, R each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. n is 0 or 1and k is an integer of 0 to 4. mm is an integer of 3 to 11 and p is aninteger of 1 to 3. Side chains X can be identical or different and eachexpressed by one of the following general Formulae (X)-1 to (X)-3. Sidechains Y can be identical or different, each representing a hydrogenatom or a straight, branched or cyclic alkyl group containing from 1 to20 carbons, which may comprise an ether group or a hydroxyl group.Further, Xs may combine with each other to form a ring. Herein, R³⁰⁰,R³⁰² and R³⁰⁵ are each a straight or branched alkylene group containingfrom 1 to 4 carbons, R³⁰¹ and R³⁰⁴ are each a hydrogen atom or astraight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether groups,ester groups and/or lactone rings. R³⁰³ is a straight or branchedsingle-bond alkylene group containing from 1 to 4 carbons, and R³⁰⁶ is astraight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether groups,ester groups and/or lactone rings.)

(In the Formula, Rs each represent, independently with one another, ahydrogen atom or a straight, branched or cyclic alkyl or alkoxy groupcontaining from 1 to 4 carbons with or without substitution. N is 0 or1, and k is an integer of 0 to 4. A side chain X can be expressed by oneof the following general Formulae (X)-1 to (X)-3. mm is an integer of 3to 11 and R³⁰⁷ is a straight or branched alkylene group containing from2 to 20 carbons, which may comprise one or more carbonyl groups, ethergroups, ester groups and/or sulfides.)

An acid generated from the photo acid generator is normally a sulfonicacid, and a salt which, being formed from the quencher and the organicpeeling agent, permeates into the resist from the outside and causes thelowering of the exposure sensitivity of the resist is an organic amine.As a result, a salt having a buffering function to maintain a pH of theacid generated from the acid generator is preferably a salt made of anacid containing a sulfonic acid and an organic amine.

The present inventors and others found out that a salt of along chainalkylbenzenesulfonic acid or a long chain alkoxybenzenesulfonic acid andan organic amine that is a basic compound is well suited and come to thepresent invention. For a part expressed by [CH3—(CH2)x-] in the Formulae(1), (1a) and (1b), it is preferable to set x large. x is preferably 3or greater and more preferably 5 or greater.

In FIG. 4, with x of not less than 3, in the resist pattern for the viahole formation, no faulty development in which residual of the holeoccurs was observed. However, when the connection test for the upper andlower layer interconnections was conducted after the via hole formation,0.1% of the connections were recognized to be faulty. With x of not lessthan 5, no faulty connection was detected.

In effect, if x is made large, an additional surface active effect isgiven to the salt having the buffer function of a sulfonic acid and anorganic amine that is a basic compound so that the number of defects canbe reduced.

When the number of oxygen atom is not greater than 1, the residual ofthe via holes was not detected.

Further, although the buffering function for an imported base over thepH of the acid generated from the acid generator has a tendency todepend on the type of the imported base, if that base is an organicamine contained in an organic peeling agent on the market, for instance,any one of primary, secondary and tertiary aliphatic amines, mixedamines, aromatic amines, heterocyclic amines, nitrogen-containingcompounds with a carboxy group, nitrogen-containing compounds with asulfonyl group, nitrogen-containing compounds with a hydroxy group,nitrogen-containing compounds with a hydroxyphenyl group, alcoholicnitrogen-containing compounds, nitrogen-containing compounds with acyano group, amide derivatives, imide derivatives andnitrogen-containing compounds which comprise further one or more oxygenatoms, being expressed by the aforementioned Formulae (1), (1a) or (1b),no residual of the via hole or abnormal trench form is observed.

A preferable combination of an acid and a basic compound is as follows.For a long chain alkylbenzenesulfonic acid or a long chainalkoxybenzenesulfonic acid, there can be given 4-n-hexylphenylsulfonicacid, 4-n-octylphenylsulfonic acid, 4-n-decylphenylsulfonic acid,4-n-dodecylphenylsulfonic acid, 4-(n-hexyloxy)phenylsulfonic acid,4-(n-octyloxy)phenylsulfonic acid, 4-(n-decyloxy)phenylsulfonic acid,4-(n-dodecyloxy)phenylsulfonic acid,3-methyl-4-(n-hexyloxy)phenylsulfonic acid,3-methyl-4-(n-octyloxy)phenylsulfonic acid,3-methyl-4-(n-decyloxy)phenylsulfonic acid,3-methyl-4-(n-dodecyloxy)phenylsulfonic acid,2-methyl-4-(n-hexyloxy)phenylsulfonic acid,2-methyl-4-(n-octyloxy)phenylsulfonic acid,2-methyl-4-(n-decyloxy)phenylsulfonic acid,2-methyl-4-(n-dodecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-hexyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-octyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-decyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-dodecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-hexyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-octyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonic acid and5-isopropyl-2-methyl-4-(n-dodecyloxy)phenylsulfonic acid. For a basiccompound, there can be given tris(2-hydroxyethyl)amine,tris(2-methoxymethoxyethyl)amine, tris(2-acetoxyethyl)amine,tris(2-propionyloxyethyl)amine, tris(2-butyryloxyethyl)amine,tris(2-isobutyryloxyethyl)amine, tris(2-valeryloxyethyl)amine,tris(2-pivaloyloxyethyl)amine, 4-[2-(methoxymethoxy)ethyl]morpholine,4-[2-[(2-methoxyethoxy)methoxy)ethyl]morpholine,4-(2-acetoxyethyl)morpholine, 4-(2-pivaloyloxyethyl)morpholine and4-[2-(ethoxycarbonyloxy)propyl]morpholine. For a salt, there can begiven, but not limited to, a combination of the above groups.

The above combinations can be expressed by the Formula (1a) (wherein Reach represent, independently with one another, a hydrogen atom or astraight, branched or cyclic alkyl or alkoxy group containing from 1 to4 carbons with or without substitution. N is 0 or 1, and k is an integerof 0 to 2. Mm is an integer of 5 to 11 and p is an integer of 1 to 3.Side chains X can be identical or different and each expressed by one ofthe Formulae (X)-1 to (X)-3. Side chains Y each represent, independentlywith one another, a hydrogen atom or a straight, branched or cyclicalkyl group containing from 1 to 8 carbons, which may comprise an etherbond or a hydroxyl group. Further, Xs may combine with each other toform a ring. Herein, R³⁰⁰, R³⁰² and R³⁰⁵ are each a straight or branchedalkylene group containing from 1 to 4 carbons, R³⁰¹ and R³⁰⁴ are each ahydrogen atom or a straight, branched or cyclic alkyl group containingfrom 1 to 8 carbons, which may comprise one or more hydroxy groups,ether bonds, ester bonds and/or lactone rings. R³⁰³ is a straight orbranched single-bond alkylene group containing from 1 to 4 carbons, andR³⁰⁶ is a straight, branched or cyclic alkyl group containing from 1 to8 carbons, which may comprise one or more hydroxy groups, ether bondsand/or ester bonds.) and Formula (1b) (wherein R each represent,independently with one another, a hydrogen atom or a straight, branchedor cyclic alkyl or alkoxy group containing from 1 to 4 carbons with orwithout substitution. n is 0 or 1 and k is an integer of 0 to 2. Sidechains X can be identical or different and each expressed by one of theFormulae (X)-1 to (X)-3. mm is an integer of 5 to 11 and R³⁰⁷ is astraight or branched alkylene group containing from 2 to 6 carbons,which may comprise one or more carbonyl bonds and/or ether bonds.)

Further, examples of a long chain alkylbenzenesulfonic acid or a longchain alkoxybenzenesulfonic acid include 4-n-butylphenylsulfonic acid,4-n-pentylphenylsulfonic acid, 4-n-hexylphenylsulfonic acid,4-n-heptylphenylsulfonic acid, 4-n-octylphenylsulfonic acid,4-n-nonylphenylsulfonic acid, 4-n-decylphenylsulfonic acid,4-n-undecylphenylsulfonic acid, 4-n-dodecylphenylsulfonic acid,4-n-tridecylphenylsulfonic acid, 4-n-tetradecylphenylsulfonic acid,4-n-pentadecylphenylsulfonic acid, 4-n-hexadecylphenylsulfonic acid,4-n-heptadecylphenylsulfonic acid, 4-n-octadecylphenylsulfonic acid,4-n-nonadecylphenylsulfonic acid, 4-n-icosylphenylsulfonic acid,4-n-henicosylphenylsulfonic acid, 4-n-docosylphenylsulfonic acid,4-n-tricosylphenylsulfonic acid, 4-n-tetracosylphenylsulfonic acid,4-(n-butyloxy)phenylsulfonic acid, 4-(n-pentyloxy)phenylsulfonic acid,4-(n-hexyloxy)phenylsulfonic acid, 4-(n-heptyloxy)phenylsulfonic acid,4-(n-octyloxy)phenylsulfonic acid, 4-(n-nonyloxy)phenylsulfonic acid,4-(n-decyloxy)phenylsulfonic acid, 4-(n-undecyloxy)phenylsulfonic acid,4-(n-dodecyloxy)phenylsulfonic acid, 4-(n-tridecyloxy)phenylsulfonicacid, 4-(n-tetradecyloxy)phenylsulfonic acid,4-(n-pentadecyloxy)phenylsulfonic acid, 4-(n-hexadecyloxy)phenylsulfonicacid, 4-(n-heptadecyloxy)phenylsulfonic acid,4-(n-octadecyloxy)phenylsulfonic acid, 4-(n-nonadecyloxy)phenylsulfonicacid, 4-(n-icosyloxy)phenylsulfonic acid,4-(n-henicosyloxy)phenylsulfonic acid, 4-(n-docosyloxy)phenylsulfonicacid, 4-(n-tricosyloxy)phenylsulfonic acid,4-(n-tetracosyloxy)phenylsulfonic acid,3-methyl-4-(n-butyloxy)phenylsulfonic acid,3-methyl-4-(n-pentyloxy)phenylsulfonic acid,3-methyl-4-(n-hexyloxy)phenylsulfonic acid,3-methyl-4-(n-heptyloxy)phenylsulfonic acid,3-methyl-4-(n-octyloxy)phenylsulfonic acid,3-methyl-4-(n-nonyloxy)phenylsulfonic acid,3-methyl-4-(n-decyloxy)phenylsulfonic acid,3-methyl-4-(n-undecyloxy)phenylsulfonic acid,3-methyl-4-(n-dodecyloxy)phenylsulfonic acid,3-methyl-4-(n-tridecyloxy)phenylsulfonic acid,3-methyl-4-(n-tetradecyloxy)phenylsulfonic acid,3-methyl-4-(n-pentadecyloxy)phenylsulfonic acid,3-methyl-4-(n-hexadecyloxy)phenylsulfonic acid,3-methyl-4-(n-heptadecyloxy)phenylsulfonic acid,3-methyl-4-(n-octadecyloxy)phenylsulfonic acid,3-methyl-4-(n-nonadecyloxy)phenylsulfonic acid,3-methyl-4-(n-icosyloxy)phenylsulfonic acid,3-methyl-4-(n-henicosyloxy)phenylsulfonic acid,3-methyl-4-(n-docosyloxy)phenylsulfonic acid,3-methyl-4-(n-tricosyloxy)phenylsulfonic acid,3-methyl-4-(n-tetracosyloxy)phenylsulfonic acid,2-methyl-4-(n-butyloxy)phenylsulfonic acid,2-methyl-4-(n-pentyloxy)phenylsulfonic acid,2-methyl-4-(n-hexyloxy)phenylsulfonic acid,2-methyl-4-(n-heptyloxy)phenylsulfonic acid,2-methyl-4-(n-octyloxy)phenylsulfonic acid,2-methyl-4-(n-nonyloxy)phenylsulfonic acid,2-methyl-4-(n-decyloxy)phenylsulfonic acid,2-methyl-4-(n-undecyloxy)phenylsulfonic acid,2-methyl-4-(n-dodecyloxy)phenylsulfonic acid,2-methyl-4-(n-tridecyloxy)phenylsulfonic acid,2-methyl-4-(n-tetradecyloxy)phenylsulfonic acid,2-methyl-4-(n-pentadecyloxy)phenylsulfonic acid,2-methyl-4-(n-hexadecyloxy)phenylsulfonic acid,2-methyl-4-(n-heptadecyloxy)phenylsulfonic acid,2-methyl-4-(n-octadecyloxy)phenylsulfonic acid,2-methyl-4-(n-nonadecyloxy)phenylsulfonic acid,2-methyl-4-(n-icosyloxy)phenylsulfonic acid,2-methyl-4-(n-henicosyloxy)phenylsulfonic acid,2-methyl-4-(n-docosyloxy)phenylsulfonic acid,2-methyl-4-(n-tricosyloxy)phenylsulfonic acid,2-methyl-4-(n-tricosyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-butyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-pentyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-hexyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-heptyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-octyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-nonyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-decyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-undecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-dodecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-tridecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-tetradecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-pentadecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-hexadecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-heptadecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-octadecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-nonadecyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-icosyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-henicosyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-docosyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-tricosyloxy)phenylsulfonic acid,3,5-dimethyl-4-(n-tetracosyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-butyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-pentyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-hexyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-heptyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-octyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-nonyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-undecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-dodecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-tridecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-tetradecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-pentadecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-hexadecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-heptadecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-octadecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-nonadecyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-icosyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-henicosyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-docosyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-tricosyloxy)phenylsulfonic acid,5-isopropyl-2-methyl-4-(n-tetracosyloxy)phenylsulfonic acid,2-(n-butyloxy)-5-methylphenylsulphonic acid,2-(n-butyloxy)-5-ethyphenylsulphonic acid,2-(n-butyloxy)-5-isopropylphenylsulphonic acid,2-(n-hexyloxy)-5-methylphenylsulphonic acid,2-(n-hexyloxy)-5-ethylphenylsulphonic acid,2-(n-hexyloxy)-5-isopropylphenylsulphonic acid,2-(n-hexyloxy)-5-tert-butylphenylsulphonic acid,2-(n-hexyloxy)-5-cyclohexylphenylsulphonic acid,2-(n-octyloxy)-5-methylphenylsulphonic acid,2-(n-dodecyloxy)-5-methylphenylsulphonic acid,2,4-(n-butyloxy)phenylsulphonic acid, 2,5-(n-butyloxy)phenylsulphonicacid, 2-methyl-4,5-(n-butyloxy)phenylsulphonic acid and2-methyl-4,5-(n-hexyloxy)phenylsulphonic acid.

As an organic amine that is a basic compound, examples of a primaryalipatic amine include ammonia, methylamine, ethylamine, n-propylamine,isopropylamine, n-butylamine, isobutylamine, sec-butylamine,tert-butylamine, pentylamine, tert-amylamine, cyclopentylamine,hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine,decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamineand tetraethylenepentamine, and examples of a secondary aliphatic amineinclude dimethylamine, diethylamine, di-n-propylamine, diisopropylamine,di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine,dicyclopentylamine, dihexylamine, dicyclohexylamine, diheptylamine,dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine,N,N-dimethylmethylenediamine, N,N-dimethylethylenediamine andN,N-dimethyltetraethylenepentamine, and examples of a tertiary aliphaticamine include trimethylamine, triethylamine, tri-n-propylamine,triisopropylamine, tri-n-butylamine, triisobutylamine,tri-sec-butylamine, tripentylamine, tricyclopentylamine, trihexylamine,tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine,tridecylamine, tridodecylamine, tricetylamine,N,N,N′,N′-tetramethylmethylenediamine,N,N,N′,N′-tetramethylethylenediamine andN,N,N′,N′-tetramethyltetraethylenepentamine.

There can be given, for mixed amines, dimethylethylamine,methylethylpropylamine, benzylamine, phenethylamine andbenzyldimethylamine; for aromatic amines and heterocyclic amines,aniline derivatives (such as aniline, N-methylaniline, N-ethylaniline,N-propylaniline, N,N-dimethylaniline, 2-methylaniline, 3-methylaniline,4-methylaniline, ethylaniline, propylaniline, trimethylaniline,2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline,2,6-dinitroaniline, 3,5-dinitroaniline and N,N-dimethyltoluidine),diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine,phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives(such as pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethylpyrrole,2,5-dimethylpyrrole, N-methylpyrrole), oxazole derivatives (such asoxazole and isoxazole), thiazole derivatives (such as thiazole andisothiazole), imidazole derivatives (such as imidazole,4-methylimidazole and 4-methyl-2-phenylimidazole), pyrazole derivatives,furazane derivatives, pyrroline derivatives (such as pyrroline and2-methyl-1-pyrroline), pyrrolidine derivatives (such as pyrrolidine,N-methylpyrrolidine, pyrrolidinone and N-methylpyrrolidone), imidazolinederivatives, imidazolidine derivatives, pyridine derivatives (such aspyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine,4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine,triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine,4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine,butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone,4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine,2-(1-ethylpropyl)pyridine, aminopyridine and dimethylaminopyridine),pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives,pyrazoline derivatives, pyrazolidine derivatives, piperidinederivatives, piperazine derivatives, morpholine derivatives, indolederivatives, isoindole derivatives, 1H-indazole derivatives, indolinederivatives, quinoline derivatives (such as quinoline and3-quinolinecarbonitrile), isoquinoline derivatives, cinnolinederivatives, quinazoline derivatives, quinoxaline derivatives,phthalazine derivatives, purine derivatives, pteridine derivatives,carbazole derivatives, phenanthridine derivatives, acridine derivatives,phenazine derivatives, 1,10-phenanthroline derivatives, adeninederivatives, adenosine derivatives, guanine derivatives, guanosinederivatives, uracil derivatives and uridine derivatives. There can begiven, for nitrogen-containing compounds with a carboxy group,aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (suchas nicotinic acid, alanine, arginine, aspartic acid, glutamic acid,glycine, histidine, isoleucine, glycylleucine, leucine, methionine,phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid andmethoxyalanine); for nitrogen-containing compounds with a sulfonylgroup, 3-pyridinesulfonic acid; for nitrogen-containing compounds with ahydroxy group, nitrogen-containing compounds with a hydroxyphenyl groupand alcoholic nitrogen-containing compounds, 2-hydroxypyridine,aminocresol, 2,4-quinolinediol, 3-indolemethanol hydrate,monoethanolamine, diethanolamine, triethanolamine,N-ethyldiethanolamine, N,N-diethylethanolamine, triisopropanolamine,2,2′-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol,4-amino-1-butanol, 4-(2-hydroxyethyl)morpholine,2-(2-hydroxyethyl)pyridine, 1-(2-hydroxyethyl)piperazine,1-[2-(2-hydroxyethoxy)ethyl]piperazine, piperidineethanol,1-(2-hydroxyethyl)pyrrolidine, 1-(2-hydroxyethyl)-2-pyrrolidinone,3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propanediol,8-hydroxypyrrolidine, 3-quinuclidinol, 3-tropanol,1-methyl-2-pyrrolizineethanol, 1-aziridineethanol,N-(2-hydroxyethyl)phthalimide and N-(2-hydroxyethyl)isonicotinamide; andfor nitrogen-containing compounds with a cyano group,3-(diethylamino)propiononitrile,N,N-bis(2-hydroxyethyl)-3-aminopropiononitrile,N,N-bis(2-acetoxyethyl)-3-aminopropiononitrile,N,N-bis(2-formyloxyethyl)-3-aminopropiononitrile,N,N-bis(2-methoxyethyl)-3-aminopropiononitrile,N,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropiononitrile, methylN-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropionate, methylN-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropionate, methylN-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropionate,N-(2-cyanoethyl)-N-ethyl-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-hydroxyethyl)-3-aminopropiononitrile,N-(2-acetoxyethyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-formyloxyethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(2-methoxyethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-[2-(methoxymethoxy)ethyl]-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(3-hydroxy-1-propyl)-3-aminopropiononitrile,N-(3-acetoxy-1-propyl)-N-(2-cyanoethyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-(3-formyloxy-1-propyl)-3-aminopropiononitrile,N-(2-cyanoethyl)-N-tetrahydrofurfuryl-3-aminopropiononitrile,N,N-bis(2-cyanoethyl)-3-aminopropiononitrile, diethylaminoacetonitrile,N,N-bis(2-hydroxyethyl)aminoacetonitrile,N,N-bis(2-acetoxyethyl)aminoacetonitrile,N,N-bis(2-formyloxyethyl)aminoacetonitrile,N,N-bis(2-methoxyethyl)aminoacetonitrile,N,N-bis[2-methoxymethoxy]ethyl)aminoacetonitrile, methylN-cyanomethyl-N-(2-methoxyethyl)-3-aminopropionate, methylN-cyanomethyl-N-(2-hydroxyethyl)-3-aminopropionate, methylN-(2-acetoxyethyl)-N-cyanomethyl-3-aminopropionate,N-cyanomethyl-N-(2-hydroxyethyl)aminoacetonitrile,N-(2-acetoxyethyl)-N-(cyanomethyl)aminoacetonitrile,N-cyanomethyl-N-(2-formyloxyethyl)aminoacetonitrile,N-cyanomethyl-N-(2-methoxyethyl)aminoacetonitrile,N-cyanomethyl-N-[2-(methoxymethoxy)ethyl]aminoacetonitrile,N-cyanomethyl-N-(3-hydroxy-1-propyl)aminoacetonitrile,N-(3-acetoxy-1-propyl)-N-(cyanomethyl)aminoacetonitrile,N-cyanomethyl-N-(3-formyloxy-1-propyl)aminoacetonitrile,N,N-bis(cyanomethyl)aminoacetonitrile, 1-pyrrolidinepropiononitrile,1-piperidinepropiononitrile, 4-morpholinepropiononitrile,1-pyrrolidineacetonitrile, 1-piperidineacetonitrile,4-morpholineacetonitrile, cyanomethyl 3-diethylaminopropionate,cyanomethyl N,N-bis(2-hydroxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-acetoxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-formyloxyethyl)-3-aminopropionate, cyanomethylN,N-bis(2-methoxyethyl)-3-aminopropionate, cyanomethylN,N-bis[2-(methoxymethoxy)ethyl]-3-aminopropionate, 2-cyanoethylN,N-bis(2-hydroxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-acetoxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-formyloxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis(2-methoxyethyl)-3-aminopropionate, 2-cyanoethylN,N-bis[2-(methoxymethoxy)ethyl)-3-aminopropionate, cyanomethyl1-pyrrolidinepropionate, cyanomethyl 1-piperidinepropionate, cyanomethyl4-morpholinepropionate, 2-cyanoethyl 1-pyrrolidinepropionate,2-cyanoethyl 1-piperidinepropionate and 2-cyanoethyl4-morpholinepropionate; for amide derivatives, formamide,N-methylformamide, N,N-diimethylformamide, acetamide, N-methylacetamide,N,N-dimethylacetamide, propionamide and benzamide; and for imidederivatives, phthalimide, succinimide and maleimide.

Further, there can be given, for nitrogen-containing compounds whichcomprises one or more oxygen atoms, tris(2-hydroxyethyl)amine,tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine,tris{2-(2-methoxyethoxymethoxy)ethyl}amine,tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine,tris{2-(1-ethoxypropoxy)ethyl}amine,tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine,4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane,4,7,13,18-tetraoxa-1,10-diazabicyclo[8,5,5]eicosane,1,4,10,13-tetraoxa-7,16-diazabicyclooctadecane,1-aza-12-crown-4,1-aza-15-crown-5,1-aza-[8-crown-6,tris(2-formyloxyethyl)amine, tris(2-acetoxyethyl)amine,tris(2-propionyloxyethyl)amine, tris(2-butyryloxyethyl)amine,tris(2-isobutyryloxyethyl)amine, tris(2-valeryloxyethyl)amine,tris(2-pivaloyloxyethyl)amine,N,N-bis(2-acetoxyethyl)-2-(acetoxyacetoxy)ethylamine,tris(2-methoxycarbonyloxyethyl)amine,tris(2-tert-butoxycarbonyloxyethyl)amine,tris[2-(2-oxopropoxy)ethyl]amine,tris[2-(methoxycarbonylmethyl)oxyethyl]amine,tris[2-(tert-butoxycarbonylmethyloxy)ethyl]amine,tris[2-(cyclohexyloxycarbonylmethyloxy)ethyl]amine,tris(2-methoxycarbonylethyl)amine, tris(2-ethoxycarbonylethyl)amine,N,N-bis(2-hydroxyethyl)-2-(methoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(methoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-ethoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-ethoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-methoxyethoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-hydroxyethoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-acetoxyethoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]ethylamine,N,N-bis(2-acetoxyethyl)-2-[(methoxycarbonyl)methoxycarbonyl]ethylamine,N,N-bis(2-hydroxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(2-oxopropoxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)ethylamine,N,N-bis(2-acetoxyethyl)-2-(tetrahydrofurfuryloxycarbonyl)ethylamine,N,N-bis(2-hydroxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxycarbonyl]ethylamine,N,N-bis(2-acetoxyethyl)-2-[(2-oxotetrahydrofuran-3-yl)oxycarbonyl]ethylamine,N,N-bis(2-hydroxyethyl)-2-(4-hydroxybutoxycarbonyl)ethylamine,N,N-bis(2-formyloxyethyl)-2-(4-formyloxybutoxycarbonyl)ethylamine,N,N-bis(2-formyloxyethyl)-2-(2-formyloxyethoxycarbonyl)ethylamine,N,N-bis(2-methoxyethyl)-2-(methoxycarbonyl)ethylamine,N-(2-hydroxyethyl)bis[2-(methoxycarbonyl)ethyl]amine,N-(2-acetoxyethyl)bis[2-(methoxycarbonyl)ethyl]amine,N-(2-hydroxyethyl)bis[2-(ethoxycarbonyl)ethyl]amine,N-(2-acetoxyethyl)bis[2-(ethoxycarbonyl)ethyl]amine,N-(3-hydroxy-1-propyl)bis[2-(methoxycarbonyl)ethyl]amine,N-(3-acetoxy-1-propyl)bis[2-(methoxycarbonyl)ethyl]amine,N-(2-methoxyethyl)bis[2-(methoxycarbonyl)ethyl]amine,N-butylbis[2-(methoxycarbonyl)ethyl]amine,N-butylbis[2-(2-methoxyethoxycarbonyl)ethyl]amine,N-methylbis(2-acetoxyethyl)amine, N-ethylbis(2-acetoxyethyl)amine,N-methylbis(2-pivaloyloxyethyl)amine,N-ethylbis[2-(methoxycarbonyloxy)ethyl]amine,N-ethylbis[2-(tert-butoxycarbonyloxy)ethyl]amine,tris(methoxycarbonylmethyl)amine, tris(ethoxycarbonylmethyl)amine,N-butylbis(methoxycarbonylmethyl)amine,N-hexylbis(methoxycarbonylmethyl)amine andβ-(diethylamine)-δ-valerolactone. Further examples include4-(2-acetoxyethyl)morpholine, 4-(2-pivaloyloxyethyl)morpholine,4-[2-(ethoxycarbonyloxy)propyl]morpholine,1-[2-(methoxymethoxy)ethyl]pyrrolidine,1-[2-(methoxymethoxy)ethyl]piperidine,4-[2-(methoxymethoxy)ethyl]morpholine,1-[2-[(2-methoxyethoxy)methoxy]ethyl]pyrrolidine,1-[2-[(2-methoxyethoxy)methoxy]ethyl]piperidine,4-[2-[(2-methoxyethoxy)methoxy]ethyl]morpholine, 2-(1-pyrrolidinyl)ethylacetate, 2-piperidinoethyl acetate, 2-morpholinoethyl acetate,2-(1-pyrrolidinyl)ethyl formate, 2-piperidinoethyl propionate,2-morpholinoethyl acetoxyacetate, 2-(1-pyrrolidinyl)ethylmethoxyacetate, 4-[2-(methoxycarbonyloxy)ethyl]morpholine,1-[2-(t-butoxycarbonyloxy)ethyl]piperidine,4-[2-(2-methoxyethoxycarbonyloxy)ethyl]morpholine, methyl3-(1-pyrrolidinyl)propionate, methyl 3-piperidinoproprionate, methyl3-morpholinopropionate, methyl 3-(thiomorpholino)propionate, methyl2-methyl-3-(1-pyrrolidinyl)propionate, ethyl 3-morpholinopropionate,methoxycarbonylmethyl 3-piperidinopropionate, 2-hydroxyethyl3-(1-pyrrolidinyl)propionate, 2-acetoxyethyl 3-morpholinopropionate,2-oxotetrahydrofurfuryl-3-yl 3-(1-pyrrolidinyl)propionate,tetrahydrofurfuryl 3-morpholinopropionate, glycidyl3-piperidinopropionate, 2-methoxyethyl 3-morpholinopropionate,2-(2-methoxyethoxy)ethyl 3-(1-pyrrolidinyl)propionate, butyl3-morpholinopropionate, cyclohexyl 3-piperidinopropionate,α-(1-pyrrolidinyl)methyl-γ-butyrolactone, β-piperidino-γ-butyrolactone,β-morpholino-δ-valerolactone, methyl 1-pyrrolidinylacetate, methylpiperidinoacetate, methyl morphonolinoacetate, methylthiomorpholinoacetate, ethyl 1-pyrrolidinylacetate and 2-methoxyethylmorpholinoacetate. For a salt, there can be given, but not limited to, acombination of these groups.

These salts can be expressed by the Formula (1a) (wherein Reachrepresent, independently with one another, a hydrogen atom or astraight, branched or cyclic alkyl or alkoxy group containing from 1 to4 carbons with or without substitution. n is 0 or 1 and k is an integerof 0 to 2. mm is an integer of 5 to 11 and p is an integer of 1 to 3.Sidechains X can be identical or different and each expressed by one ofthe Formulae (X)-1 to (X)-3. Side chains Y each represent, independentlywith one another, a hydrogen atom or a straight, branched or cyclicalkyl group containing from 1 to 8 carbons, which may comprise an etherbond or a hydroxyl group. Further, Xs may combine with each other toform a ring. Herein, R³⁰⁰, R³⁰² and R³⁰⁵ are each a straight or branchedalkylene group containing from 1 to 4 carbons, R³⁰¹ and R³⁰⁴ are each ahydrogen atom or a straight, branched or cyclic alkyl group containingfrom 1 to 8 carbons, which may comprise one or more hydroxy groups,ether bonds, ester bonds and/or lactone rings. R³⁰³ is a straight orbranched single-bond alkylene group containing from 1 to 4 carbons, andR³⁰⁶ is a straight, branched or cyclic alkyl group containing from 1 to8 carbons, which may comprise one or more hydroxy groups, ether bondsand/or ester bonds.) and Formula (1b) (wherein Rs each represent,independently with one another, a hydrogen atom or a straight, branchedor cyclic alkyl or alkoxy group containing from 1 to 4 carbons with orwithout substitution. n is 0 or 1 and k is an integer of 0 to 2. A sidechain X can be expressed by one of the Formulae (X)-1 to (X)-3. mm is aninteger of 5 to 11 and R³⁰⁷ is a straight or branched alkylene groupcontaining from 2 to 6 carbons, which may comprise one or more carbonylbonds and/or ether bonds.)

The amount of addition for a salt of this sort is preferably not lessthan one time but not greater than twenty times and more preferably notless than twice but not greater than ten times the amount of additionfor the quencher.

When the amount not less than one time the amount of addition for thequencher is added, the effect of the resist poisoning can be reduced andthe resolution does not deteriorate. If it is not greater than twentytimes that, residual or faulty shape does not occur.

Now, referring to a series of schematic cross-sectional views of asubstrate illustrating the steps of a manufacturing method of asemiconductor integrated circuit device wherein the afore-mentionedchemically amplified positive resist composition is used, amanufacturing method of the present invention is described.

This method comprises the step wherein, using a chemically amplifiedpositive resist composition into which a salt of the present inventionis added 5 times as much as the amount of a quencher, a resist film (1of FIG. 1( c)) is formed on a substrate (a semiconductor substrate)having a stepped part (21 of FIG. 1( a)), and, by applying the exposureonto a prescribed region of that resist film, a resist pattern (1 ofFIG. 1( c)) is formed, and this enables to form a resist pattern of goodquality even if the photoresist is subjected to the poisoning by thepoisoning component of the organic peeling agent, which may be left inthe vicinity of the stepped part by the adhesion or such, since a basiccompound in the resist buffers to prevent the concentration of theacidic catalyst from falling fast and to allow the resist in the exposedsection to undergo efficient transformation that changes its solubilityin the resist developer solution, that is, to a higher solubility (inthe case of the positive resist) and to a lower solubility (in the caseof the negative resist).

First, on a substrate surface where a Cu lower layer interconnection isformed, the Cu lower layer interconnection being exposed, an etchingbarrier film 7 (SiCN; 70 nm in thickness), a first interlayer insulatingfilm 6 (SiO2; 250 to 400 nm in thickness), an etching barrier film 5(SiC; 50 nm in thickness), a second interlayer insulating film 4 (asilicon oxide film or a Low-k film; 200 nm in thickness) and a cap film(SiO2; 150 nm in thickness) are formed in this order from the side ofthe substrate by the CVD (Chemical Vapor Deposition) method or the spincoating method (the step A1; See FIG. 1( a)).

For the cap film 3, herein, in addition to a SiO2 film, a CMP stopperfilm of SiN, SiC, SiON, SiCN or such can be also used.

As the second interlayer insulating film 4, a silicon oxide film or aLow-k film (such as a HSQ (HydrogenSilsesQuioxane) or a Si—H containingSiO2 film; grown by the coating method; the dielectric constant k<3.0)is, in the present Example, utilized, but, not limited to this, otherLow-k films including inorganic insulating films of SiOF, SiOB, BN,SiOC, porous silica films and organic insulating films such as SiO2films containing a methyl group, polyimide based films, parylene basedfilms, polytetrafluoroethylene based films, other copolymer films andfluorine-doped amorphous carbon films may be also used.

For the etching barrier film 5, besides a SiC film, a film of SiN, SiON,SiCN or such can be used.

For the first interlayer insulating film 6, like the second interlayerinsulating film 4, a Low-k film can be used, in addition to a SiO2 film.

As the etching barrier film 7, SiC, SiN, SiON or such can be used, inaddition to SiCN. However, in the case that etching is made by adifference in etching selection ratio, a different material from that ofthe etching barrier film 5 must be employed.

Next, onto the surface of the cap film 3, a coating of a composition foranti-reflection film formation is applied (by means of spin-coating),and by carrying out the pre-bake at 200° C. for 90 seconds, ananti-reflection film is formed to a thickness of 50 nm (the step A2).After that, onto the surface of this anti-reflection film, a coating(spin-coating) of a photoresist composition (a chemically amplifiedpositive photoresist composition) is applied, and by carrying out thepre-bake with a hot plate at 95° C. for 90 seconds, a photoresist filmis formed to a thickness of 400 nm (the step A3). Subsequently, thesubstrate on which the photoresist film (chemically amplified positivephotoresist) is grown is subjected to the exposure with an optimalexposure dose and focus, using a KrF excimer laser scanner (NSR-S204B;manufactured by Nikon Co.), and, being post-baked at 105° C. for 90seconds immediately after the exposure, developed for 60 seconds in adeveloper solution that is a 2.38 wt. % aqueous solution oftetramethylammonium hydroxide (the step A4). A resist pattern for viahole formation is thereby obtained.

The composition for anti-reflection film formation is herein employed acomposition for anti-reflection film formation (Japanese PatentApplication Laid-open No. 92122/2001) manufactured by Tokyo Ohka KogyoCo., Ltd. or a composition for the anti-reflection film formation (WONo. 01752/2000) manufactured by Clariant (Japan) K. K., both of whichcontain a polymer material, an optical absorption agent (opticalabsorption site), an acidic catalyst and an organic solvent.

Next, the substrate wherein the resist pattern for via hole formation isformed is subjected to the dry etching (the plasma etching) so that thefirst anti-reflection film, the cap film 3, the second interlayerinsulating film 4 the second etching barrier film 5 and the firstinterlayer insulating film 6 may be selectively etched in successiontill the first etching barrier film 7 is exposed (the step A5), andthereby a via hole (φ0.2 μm) is formed (See FIG. 1( a)).

Next, by performing first plasma ashing and then using an organicpeeling agent, the resist pattern for via hole formation is removed fromthe substrate where the via hole formation is completed (the step A6).The cross-section of the substrate is here at in the state shown in FIG.1( a).

At this very moment, an amine component contained in the organic peelingagent is attached (adsorbed) on or seeped into the interlayer insulatingfilms 4 and 6 which are exposed within the via hole. The result ofcomponent identification conducted at this moment (after drying) for thecomponents attached onto the first interlayer insulating film 4 and thesecond interlayer insulating film 6 is shown in FIG. 3. FIG. 3 is a pairof graphs showing a result of the component identification in whichcomponents attached onto the substrate with Low-k films are extractedinto pure water after the step A6 of Example 1 and identified by thecapillary electrophoresis method (electrophelogram), together with theresult of component identification for the organic peeling agent forcomparison. The exact components of the organic peeling agent is notdisclosed, but a comparison between the graph for the organic peelingagent components and the graph for the components attached onto thesubstrate shows the positions of their peaks well coincide, indicatingthat the organic peeling agent remains attached onto the substrate, evenafter the resist is peeled off and dried.

It is a hard task to remove amine components from the first interlayerinsulating film 4 and the second interlayer insulating film 6 bycleaning and such, once they are attached thereon. In some cases,certain heat treatments or the like are conducted for the purpose ofreducing the amount of amine components attached onto the firstinterlayer insulating film 4 and the second interlayer insulating film6, but it is technically difficult to remove amine components thoroughlydue to restriction on the temperature imposed for other interconnectionlayers. The organic peeling agent used herein is a mixed organicalkaline solution on the market, and thought to contain amine componentssuch as ethylenediamine, monoethanolamine, methylamine, triethanolamineand methylmonoethanolamine, but its exact chemical composition is notdisclosed. Some description of amine components contained in organicpeeling agents can be found in Japanese Patent Application Laid-open No.331541/1994, Japanese Patent Application Laid-open No. 226696/2001 andJapanese Patent Application Laid-open No. 89488/2000.

Next, a coating (spin-coating) of a composition for anti-reflection filmformation is applied onto the substrate surface from which the resistpattern for via hole formation has been removed, and by carrying out thepre-bake at 200° C. for 90 seconds, an anti-reflection film 2 is formedto a thickness of 50 nm (the film thickness on the surface of the capfilm 3) (the step A7). This provides the anti-reflection film over thesurface of the sidewall of the via hole very thinly, while theanti-reflection film accumulates thick at the bottom of the via hole(the via hole is not entirely filled up) (See FIG. 1( b)).

Here at, in carrying out the pre-bake of the anti-reflection film 2,some amine components attached onto the first interlayer insulating film4 and the second interlayer insulating film 6 may be released into theair, but it is considered that a good deal of amine components remainattached onto the first interlayer insulating film 4 and the secondinterlayer insulating film 6 or present in the anti-reflection film 2.This anti-reflection film 2 is made of the same material as theafore-mentioned anti-reflection film used for via hole formation.

Next, a coating (spin-coating) of a photoresist composition (achemically amplified positive photoresist composition) is applied ontothe surface of the anti-reflection film 2, and by carrying out thepre-bake with a hot plate at 95° C. for 90 seconds, a photoresist film 1is formed to a thickness of 400 nm (the film thickness on the surface ofthe cap film 3) (the step A8). In this way, the photoresist film 1 isformed to fill up the via hole (See FIG. 1( c)).

At the time of the pre-bake performed for the photoresist 1, the aminecomponents which remain attached onto the first interlayer insulatingfilm 4 and the second interlayer insulating film 6 or present in theanti-reflection film 2 may permeate into the photoresist 1, passingthrough the anti-reflection film 2. The original liquid employed for thephotoresist 1 is the same as the one for the photoresist (chemicallyamplified positive photoresist composition) for via hole formation.

Next, the substrate on which the photoresist film 1 is formed issubjected to the exposure with an optimal exposure dose and focus, usingthe KrF excimer laser scanner (NSR-S204B; manufactured by Nikon Co.),and, being post-baked at 105° C. for 90 seconds immediately after theexposure, developed for 60 seconds in a developer solution that is a2.38 wt. % aqueous solution of tetramethylammonium hydroxide (the stepA9). A resist pattern for interconnection trench formation (a resistpattern having, on the substrate, an opening section in the region whichincludes the lateral face of the wall of the stepped part) is therebyobtained (See FIG. 1( d)).

Herein, in contrast with the case wherein a conventional photoresist isused, any photoresist which may cause resolution defects does not remainwithin the via hole or in its vicinity, and the exposed photoresist canbe removed with the developer solution.

On exposure, generation of acids takes place. It is considered that theacids are not necessarily completely dissociated in the solid, butdissociated with a certain degree of dissociation. In general, thedissociation constant of the acid in the solid (in the resist) isthought to be low. When a salt of an organic sulfonic acid derivativethat comprises a conjugate base for the acid to be generated and anorganic amine that is a basic compound is added as an additive for thebuffering effect, the acid dissociation equilibrium shifts towards thenon-dissociation, owing to the presence of the conjugate base. In thiscondition, even if impurities of basicity such as amines permeates intothe photoresist from the outside, the basic substances such as aminesare neutralized by the nondissociated acids abundantly present therein.Therefore, the change of concentration of the acids acting as effectivecatalyst (dissociated acids) is small. Even if the dissociated acids areneutralized, the acid dissociation equilibrium shifts towards thedissociation so that the change of concentration of the acids acting aseffective catalyst (dissociated acids) is small. When impurities ofstrong acidity enter, the buffering action takes place, as negative ionsof the salt neutralize the acids.

Further, with the buffering effect functioning, the pH of the resist isless affected by the fluctuation of the exposure dose (that is, theamount of the generated acids) and, therefore, the margin against theexposure dose increases.

Next, the substrate where the formation of the resist pattern forinterconnection trench pattern is completed is etched by the dry etchingmethod from the top surface layer so as to etch selectively the secondanti-reflection film 2, the cap film 3, the second interlayer insulatingfilm 4, in succession, till the second etching barrier film 5 is exposed(the step A10), and thereby an interconnection trench 22 is formed (SeeFIGS. 1( e) and (f)).

Next, from the substrate where the interconnection trench formation iscompleted, the resist pattern for resist pattern formation is removed byperforming first plasma ashing and then using an organic peeling agent(the step A11).

Next, in the substrate from which the resist pattern for interconnectiontrench formation has been removed, the exposed etching barrier film 7 isetched by the etch back method, till the Cu lower layer interconnectionlayer 8 is exposed (the step A12). This leaves the cross-section of thesubstrate in the state shown in FIG. 1( g).

Finally, after cleaning the substrate where a part of the Cu lower layerinterconnection layer is exposed, a Cu plating film 9 is grown on thesubstrate surface by the CVD method (so as to fill up the via hole andthe interconnection trench), and then the planarization is carried outby the CMP (till the second interlayer insulating film 4 is exposed)(the step A13). A dual damascene interconnection 9 that is electricallyconnected with the Cu lower layer interconnection layer 8 is therebyformed (See FIG. 1( h)).

In the present Example, the photoresist within the via hole 21 can beresolved well by irradiation and does not remain after the treatmentwith the developer solution (See FIG. 1( d)).

Next, the relationship between the composition of the chemicallyamplified positive photoresist and the trimming quality or the form ofthe via hole was investigated.

For the substrate 1, the same manufacturing method as the trenchinterconnection structure shown in FIG. 1 was used. The parameters forthe substrate and such are shown in Table 1. For the substrate 2, aftera HSQ film, 300 nm thick, was formed on a silicon substrate andsubsequent treatments of organic peeling-off and heat treatment (at 350°C., for 30 minutes) were conducted, a photoresist 400 nm thick (afterthe pre-bake) was formed and then a via hole with φ of 0.14 μm and a0.14 μm L/S (line and space pattern) were formed. The substrate 3 wasmanufactured in the same way as the substrate 2 except that a TiN film200 nm thick was used in place of the HSQ film on the substrate 2.

While a silicon oxide film was herein used as a typical a Low-k film ofporous film quality, it is obvious that other Low-k films includinginorganic insulating films of SiOF, SiOB, BN, SiOC, porous silica filmsand organic insulating films such as SiO2 films containing a methylgroup, polyimide based films, parylene based films,polytetrafluoroethylene based films, other copolymer films andfluorine-doped amorphous carbon films may be also used.

TABLE 1 Substrate1 Photoresist Refer Table2/400 nm Anti-Reflection Film2Tokyo Ohka Kogyo Co., Ltd./50 nm Cap Film3 SiO₂/150 nm InterlayerInsulating HSQ/200 nm Film4 Etching Barrier Film5 SiC/50 nm InterlayerInsulating SiO₂/250 nm Film6 Etching Barrier Film6 SiCN/70 nm HeatTreatment 350

/30 min. Via Hole Diameter φ0.14 μm, L/S 0.14 μm

TABLE 2 Acid Acid Organic BaseResin Generator Generator Solvent (Part by(1) (Part (2) (Part Quencher Salt (Part by Sample Weight) by Weight) byWeight) (mmol/1 kg) (mmol/1 kg) Weight) Sample1 Polymer A PAG1 PAG2Base1 PGMEA/ (100) (2) (0.6) (20) EL(60 Sample2 Polymer A PAG1 PAG2Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (5) EL(60 Sample3 Polymer A PAG1PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (20) EL(60 Sample4 PolymerA PAG1 PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (100) EL(60 Sample5Polymer A PAG1 PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (40) EL(60Sample6 Polymer A PAG1 PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20)(100) EL(60 Sample7 Polymer A PAG1 PAG2 Base1 SaltA PGMEA/ (100) (2)(0.6) (20) (200) EL(60 Sample8 Polymer A PAG1 PAG2 Base1 SaltA PGMEA/(100) (2) (0.6) (20) (400) EL(60 Sample9 Polymer A PAG1 PAG2 Base1 SaltAPGMEA/ (100) (2) (0.6) (20) (500) EL(60 Sample10 Polymer A PAG1 PAG2Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (10) EL(60 Sample11 Polymer APAG1 PAG2 Base1 SaltB PGMEA/ (100) (2) (0.6) (20) (5) EL(60 Sample12Polymer A PAG1 PAG2 Base1 SaltB PGMEA/ (100) (2) (0.6) (20) (20) EL(60Sample13 Polymer A PAG1 PAG2 Base1 SaltB PGMEA/ (100) (2) (0.6) (20)(100) EL(60 Sample14 Polymer A PAG1 PAG2 Base1 SaltB PGMEA/ (100) (2)(0.6) (20) (40) EL(60 Sample15 Polymer A PAG1 PAG2 Base1 SaltB PGMEA/(100) (2) (0.6) (20) (100) EL(60 Sample16 Polymer A PAG1 PAG2 Base1SaltB PGMEA/ (100) (2) (0.6) (20) (200) EL(60 Sample17 Polymer A PAG1PAG2 Base1 SaltB PGMEA/ (100) (2) (0.6) (20) (400) EL(60 Sample18Polymer A PAG1 PAG2 Base1 SaltB PGMEA/ (100) (2) (0.6) (20) (500) EL(60Sample19 Polymer A PAG1 PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20)(10) EL(60 Adjudication Substrate1 Exposure Resist Substrate2 Substrate3Sensi- Poison- Exposure Residual/ Residual/ Sample Residual tivity ingmargin Shape Shape Shape Sample1 X ⊚ X Δ ⊚ X X Sample2 ⊚ ⊚ X Δ ⊚ ⊚ ⊚Sample3 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample4 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample5 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample6 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample7 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample8 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample9 ◯ ⊚ ⊚ ⊚ Δ ◯ ◯ Sample10 ⊚ ⊚ Δ ◯ ⊚ ⊚ ⊚ Sample11 ⊚ ⊚ X Δ ⊚ ⊚ ⊚Sample12 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample13 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample14 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample15 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample16 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample17 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample18 ◯ ⊚ ⊚ ⊚ Δ ◯ ◯ Sample19 ⊚ ⊚ Δ ◯ ⊚ ⊚ ⊚

TABLE 3 Acid Acid Organic BaseResin Generator Generator Solvent (Part by(1) (Part (2) (Part Quencher Salt (Part by Sample Weight) by Weight) byWeight) (mmol/1 kg) (mmol/1 kg) Weight) Sample20 Polymer A PAG1 PAG2Base1 SaltA PGMEA/ (100) (5) (0.6) (20) (100) EL(60 Sample21 Polymer APAG3 PAG2 Base1 SaltA PGMEA/ (100) (5) (0.6) (20) (100) EL(60 Sample22Polymer A PAG3 PAG2 Base1 SaltA PGMEA/ (100) (2) (0.6) (20) (100) EL(60Sample23 Polymer A PAG4 Base1 SaltA PGMEA/ (100) (3) (20) (100) EL(60Sample24 Polymer A PAG5 Base1 SaltA PGMEA/ (100) (3) (20) (100) EL(60Sample25 Polymer A PAG3 PAG4 Base2 SaltA PGMEA/ (100) (2) (0.6) (20)(100) EL(60 Sample26 Polymer A PAG4 PAG5 Base3 SaltA PGMEA/ (100) (2)(0.6) (20) (100) EL(60 Sample27 Polymer A PAG1 PAG2 Base1 SaltB PGMEA/(100) (2) (0.6) (20) (100) EL(60 Sample28 Polymer A PAG1 PAG2 Base2SaltB PGMEA/ (100) (2) (0.6) (20) (100) EL(60 Sample29 Polymer A PAG1PAG2 Base3 SaltB PGMEA/ (100) (2) (0.6) (20) (100) EL(60 Sample30Polymer A PAG1 PAG2 Base1 SaltC PGMEA/ (100) (2) (0.6) (20) (100) EL(60Sample31 Polymer A PAG1 PAG2 Base2 SaltC PGMEA/ (100) (2) (0.6) (20)(100) EL(60 Sample32 Polymer A PAG1 PAG2 Base3 SaltC PGMEA/ (100) (2)(0.6) (20) (100) EL(60 Sample33 Polymer A PAG1 PAG2 Base1 SaltD PGMEA/(100) (2) (0.6) (20) (100) EL(60 Sample34 Polymer A PAG1 PAG2 Base2SaltD PGMEA/ (100) (2) (0.6) (20) (100) EL(60 Sample35 Polymer A PAG1PAG2 Base3 SaltD PGMEA/ (100) (2) (0.6) (20) (100) EL(60 AdjudicationSubstrate1 Exposure Resist Substrate2 Substrate3 Sensi- Poison- ExposureResidual/ Residual/ Sample Residual tivity ing margin Shape Shape ShapeSample20 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample21 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample22 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample23 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample24 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample25 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample26 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample27 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample28 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample29 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample30 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample31 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample32 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample33 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Sample34 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Sample35 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚

The compositions of the chemically amplified photoresists (samples) usedas the photoresist 1 are shown in Tables 2 and 3. Polymer A in the baseresin is the very resin expressed by the afore-mentioned Formula (2).The PADs 1 to 5 in the acid generator are the acid generators expressedby the afore-mentioned Formula (5). The unit used for the bases (thequenchers) is [mmol/poly-1000 g] (that is, mmol of the basic compoundper 1000 g of the base resin). In the base, “Base 1” is triethanolamine(molecular weight: 149.19), “Base 2” is tri-n-butylamine (molecularweight: 185.36) and “Base 3” is 2-butoxypyridine (molecular weight:151.21). In the organic solvent, PGMEA indicates propylene glycolmonomethyl ether acetate and EL, ethyl lactate.

Further, Salt A is 4-n-dodecylphenylsulfonic acidtris(2-hydroxyethyl)amine; Salt B,3,5-dimethyl-4-(n-hexyloxy)phenylsulfonicacid-4-(2-acetoxyethyl)morpholine; Salt C,5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonic acidtris(2-isobutyryloxyethyl)amine; Salt D, 4-n-dodecylphenylsulfonic acidtris(2-methoxymethoxyethyl)amine and Salt E,2-methyl-4-(n-dodecyloxy)phenylsulfonic acid tris(2-acetoxyethyl)amine.

The Exposure was made by the KrF excimer laser (wavelength: 248 nm) at45 mJ/cm2. The ArF excimer laser (wavelength: 193 nm) and the electronbeam direct drawing exposure apparatus (50 keV) were also used in themeasurements for the systems of the sample 4 with replaced polymers, theresults of which were essentially the same as those obtained with theKrF excimer laser.

Two types of laser beams with a wavelength of 248 nm and with awavelength of 193 nm as well as the electron beam direct drawingexposure were successfully used to generate the acids and make theexposure. This shows possibilities of the application for the F2 excimerlaser and the atomic beam exposure, both of which have even shorterwavelengths.

Further, for the substrates 1-3, qualitative examinations were conductedunder the microscope with the eye, and after 100 points were inspectedfor each substrate, the following marking was made.

1. Residual: The sample was marked with ⊚ for none of residual; with ∘for 10% or less; with Δ, for 10 to 15% and with x for 15% or more.

2. Shape: Regarding the L/S shape, the sample was marked with ⊚ for noneof defective shape; with ∘ for 10% or less; with Δ for 10 to 15% andwith x for 15% or more.

3. Exposure sensitivity: The sample was marked with ⊚ for 150 mJ/cm2 orless; with ∘ for greater than 150 mJ/cm2 but not greater than 200mJ/cm2; with Δ, for greater than 200 mJ/cm2 but not greater than 300mJ/cm2 and with x for 300 mJ/cm2 or greater.

It is based on a fact that, with the laser exposure, if the exposuresensitivity is 200 mJ/cm2 or less, compensation can be made through thenumber of laser pulses, but if the exposure sensitivity exceeds 200mJ/cm2, compensation can be only made by lowering the scan rate. Thereduction of the scan rate lowers the throughput of the apparatus and,thus, the productivity.

4. Exposure margin: The sample was marked with ⊚ for ±15% or less; with∘ for ±10% or less; with Δ, for ±7% or less and with x for ±5% or less.The higher the exposure margin is, the higher the process margin becomesso that the manufacturing steps can have some free scope.

5. Resist poisoning: The resist poisoning was inspected throughobservations of the pattern tailing. The sample was marked with ⊚ fornone of tailing; with Δ, for tailing at more than one point but notgreater than 5% and with x for greater than 5%.

All the substrates 1 to 3 in the present Examples were marked with ⊚,while the substrates in the Cases for Comparison were not.

The results of Tables 2 and 3 indicate that as long as the amount of thesalt is not less than once but not greater than twenty times the amountof the quencher, no problem of residual, defective shape, exposuresensitivity and resist poisoning arises, regardless of the combinationof the acid generator, the quencher and the salt, but when the amount ofthe salt exceeds twenty times of the amount of the quencher, theresidual and/or defective shape may be brought about.

The sample 1 is a conventional chemically amplified resist compositioncontaining only the quencher, which has problems of the residual, theresist poisoning and the exposure margin.

However, it was shown that with an addition of 25% of the salt to theamount of the quencher the residual disappeared.

The base resins employed in these measurements were all the same. Noproblem arose with the wavelength of the laser or the electron beamexposure used in these measurements.

The results of the change in the number of carbons in the acid part ofvarious salts in the 4-n-alkylphenylsulfonic acidtris(2-hydroxyethyl)amine system are shown in FIG. 4.

In the case of salts in the 4-n-alkylphenylsulfonic acidtris(2-hydroxyethyl)amine system, similar results to that of4-n-dodecylphenylsulfonic acid tris(2-hydroxyethyl)amine were obtainedto up to 4-n-butylphenylsulfonic acid tris(2-hydroxyethyl)amine.

On the other hand, 4-n-propylphenylsulfonic acidtris(2-hydroxyethyl)amine, 4-n-ethylphenylsulfonic acidtris(2-hydroxyethyl)amine or 4-n-methylphenylsulfonic acidtris(2-hydroxyethyl)amine is utilized, the acids cannot buffer theimported base sufficiently, and defective resist patterns are produced.

Under the same conditions as the sample 4, the experiments using4-n-dodecylphenylsulfonic acid tris(2-hydroxyethyl)amine,4-n-propylphenylsulfonic acid tris(2-hydroxyethyl)amine,4-n-ethylphenylsulfonic acid tris(2-hydroxyethyl)amine and4-n-methylphenylsulfonic acid tris(2-hydroxyethyl)amine as the saltswere carried out and their results are shown in FIG. 4.

As seen clearly in FIG. 4, with 4-n-butylphenylsulfonic acidtris(2-hydroxyethyl)amine, no appearance defects arose, but for4-n-propylphenylsulfonic acid tris(2-hydroxyethyl)amine,4-n-ethylphenylsulfonic acid tris(2-hydroxyethyl)amine and4-n-methylphenylsulfonic acid tris(2-hydroxyethyl)amine, the number ofappearance defects in the resist patterns increase in this order.

These measurements were made under the same exposure conditions and thecombination of the via hole and the L/S pattern with the same dimensionsas those for Tables 2 and 3.

Accordingly, the present invention was shown to have effects by thecombinations of the acid generator, the quencher and the salt. While allthe descriptions in the Examples are made with the chemically amplifiedpositive resist, it will be obvious to those skilled in the art that theinvention is applied to the chemically amplified negative resist.

1. A method of manufacturing a semiconductor integrated circuit device,which comprises the step of performing photolithography in which acoating of a photoresist is applied onto a substrate and then anexposure and a development is carried out to form a resist pattern;wherein: a chemically amplified photoresist is used as said photoresist,the chemically amplified photoresist comprising: a photo acid generator;an amount of quencher; and a salt having a buffering function for anacid which is generated from said acid generator by irradiation in anamount that is not less than one time but not greater than ten times theamount of quencher, wherein, said salt having the buffering function forthe acid generated from said acid generator is specifically a saltderived from a long chain alkylbenzenesulfonic acid or a long chainalkoxybenzenesulfonic acid and an organic amine that is a basiccompound, being expressed by the Formula (1):

wherein each R independently represents a hydrogen atom or a straight,branched or cyclic alkyl or alkoxy group containing from 1 to 4 carbonswith or without substitution; n is 1; m is an integer of 3 to 23; k isan integer of 0 to 4; 1 is an integer of 1 to 3; and B is any one ofprimary, secondary and tertiary aliphatic amines, mixed amines, aromaticamines, heterocyclic amines, nitrogen-containing compounds with acarboxy group, nitrogen-containing compounds with a sulfonyl group,nitrogen-containing compounds with a hydroxy group, nitrogen-containingcompounds with a hydroxyphenyl group, alcoholic nitrogen-containingcompounds, nitrogen-containing compounds with a cyano group, amidederivatives, imide derivatives and nitrogen-containing compoundscomprising one or more oxygen atom.
 2. A method of manufacturing asemiconductor integrated circuit device according to claim 1, wherein anirradiation for said exposure is made with rays having a wavelength ofat least 365 nm-0.1 nm or an electron beam having an energy of 300 keV-1keV.
 3. A method of manufacturing a semiconductor integrated circuitdevice according to claim 1, wherein said step of performingphotolithography comprises the step of applying a coating of thephotoresist onto a via hole or a trench which is made in an insulatingfilm formed on the substrate and exposing a part including said via holeor said trench.
 4. A method of manufacturing a semiconductor integratedcircuit device according to claim 3, wherein said insulating filmcomprises at least one layer of a low-dielectric-constant film whosedielectric constant is not greater than
 3. 5. A method of manufacturinga semiconductor integrated circuit device according to claim 1, wherein,in said step of performing photolithography, a thin film is formed onthe substrate surface, and said thin film is a thin film including anitrogen atom in constituting atoms thereof.
 6. A method ofmanufacturing a semiconductor integrated circuit device according toclaim 5, wherein said nitrogen-containing thin film is one of TiN, SiN,SiCN and SiON films.
 7. A method of manufacturing a semiconductorintegrated circuit device, which comprises the step of performingphotolithography in which a coating of a photoresist is applied onto asubstrate and then an exposure and a development is carried out to forma resist pattern; wherein: a chemically amplified photoresist is used assaid photoresist, the chemically amplified resist compositioncomprising: a photo acid generator; a quencher; and a salt having abuffering function for an acid which is generated from said acidgenerator by irradiation, wherein, said salt having the bufferingfunction for the acid generated from said acid generator is specificallya salt derived from a long chain alkylbenzenesulfonic acid or a longchain alkoxybenzenesulfonic acid and an organic amine that is a basiccompound, being expressed by the Formula (1a):

wherein each R independently represents a hydrogen atom or a straight,branched or cyclic alkyl or alkoxy group containing from 1 to 4 carbonswith or without substitution; n is 0 or 1; k is an integer of 0 to 4; mmis an integer of 3 to 11; p is an integer of 1 to 3; side chains Y eachindependently represent a hydrogen atom or a straight, branched orcyclic alkyl group containing from 1 to 20 carbons, which may comprisean ether bond or a hydroxyl group; chains X can be identical ordifferent and each expressed by one of the Formulae (X)-1 to (X)-3; andmay combine with each other to form a ring:

R³⁰⁰, R³⁰² and R³⁰⁵ are each a straight or branched alkylene groupcontaining from 1 to 4 carbons; R³⁰¹ and R³⁰⁴ are each a hydrogen atomor a straight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether bonds,ester bonds and/or lactone rings; R³⁰³ is a straight or branched singlebond alkylene group containing from 1 to 4 carbons; and R³⁰⁶ is astraight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether bonds,ester bonds and/or lactone rings.
 8. A method of manufacturing asemiconductor integrated circuit device according to claim 7, wherein anirradiation for said exposure is made with rays having a wavelength ofat least 365 nm-0.1 nm or an electron beam having an energy of 300 keV-1keV.
 9. A method of manufacturing a semiconductor integrated circuitdevice according to claim 7, wherein said step of performingphotolithography comprises the step of applying a coating of thephotoresist onto a via hole or a trench which is made in an insulatingfilm formed on the substrate and exposing a part including said via holeor said trench.
 10. A method of manufacturing a semiconductor integratedcircuit device according to claim 9, wherein said insulating filmcomprises at least one layer of a low-dielectric-constant film whosedielectric constant is not greater than
 3. 11. A method of manufacturinga semiconductor integrated circuit device according to claim 7, wherein,in said step of performing photolithography, a thin film is formed onthe substrate surface, and said thin film is a thin film including anitrogen atom in constituting atoms thereof.
 12. A method ofmanufacturing a semiconductor integrated circuit device according toclaim 11, wherein said nitrogen-containing thin film is one of TiN, SiN,SiCN and SiON films.
 13. A method of manufacturing a semiconductorintegrated circuit device, which comprises the step of performingphotolithography in which a coating of a photoresist is applied onto asubstrate and then an exposure and a development is carried out to forma resist pattern; wherein: a chemically amplified photoresist is used assaid photoresist, the chemically amplified photoresist comprising atleast a photo acid generator, a quencher and a salt having a bufferingfunction for an acid which is generated from said acid generator byirradiation; wherein: said salt having the buffering function for theacid generated from said acid generator is specifically a salt derivedfrom a long chain alkylbenzenesulfonic acid or a long chainalkoxybenzenesulfonic acid and an organic amine that is a basiccompound, being expressed by the Formula (1b) wherein each Rindependently represents a hydrogen

atom or a straight, branched or cyclic alkyl or alkoxy group containingfrom 1 to 4 carbons with or without substitution. n is 0 or 1 and k isan integer of 0 to
 4. A side chain X can be expressed by one of theFormulae (X)-1 to (X)-3. mm is an integer of 3 to 11 and R³⁰⁷ is astraight or branched alkylene group containing from 2 to 20 carbons,which may comprise one or more carbonyl bonds, ether bonds, ester bonds,sulfide bonds, sulfinyl bonds and/or sulfonyl bonds.

R³⁰⁰, R³⁰² and R³⁰⁵ are each. a straight or branched alkylene groupcontaining from 1 to 4 carbons; R³⁰¹ and R³⁰⁴ are each a hydrogen tonior a straight. branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether bonds.ester bonds and/or lactone ring; R³⁰³ is a straight or branched singlebond alkylene group containing from 1 to 4 carbons; and R³⁰⁶ is astraight, branched or cyclic alkyl group containing from 1 to 20carbons, which may comprise one or more hydroxy groups, ether bonds,ester bonds and/or lactone rings.
 14. A method of manufacturing asemiconductor integrated circuit device according to claim 13, whereinan irradiation for said exposure is made with rays having a wavelengthof at least 365 nm-0.1 nm or an electron beam having an energy of 300keV-1 keV.
 15. A method of manufacturing a semiconductor integratedcircuit device according to claim 13, wherein said step of performingphotolithography comprises the step of applying a coating of thephotoresist onto a via hole or a trench which is made in an insulatingfilm formed on the substrate and exposing a part including said via holeor said trench.
 16. A method of manufacturing a semiconductor integratedcircuit device according to claim 15, wherein said insulating filmcomprises at least one layer of a low-dielectric-constant film whosedielectric constant is not greater than
 3. 17. A method of manufacturinga semiconductor integrated circuit device according to claim 13,wherein, in said step of performing photolithography, a thin film isformed on the substrate surface, and said thin film is a thin filmincluding a nitrogen atom in constituting atoms thereof.
 18. A method ofmanufacturing a semiconductor integrated circuit device according toclaim 17, wherein said nitrogen-containing thin film is one of TiN, SiN,SiCN and SiON films.
 19. A method of manufacturing a semiconductorintegrated circuit device, which comprises the step of performingphotolithography in which a coating of a photoresist is applied onto asubstrate and then an exposure and a development is carried out to forma resist pattern; wherein: a chemically amplified photoresist is used assaid photoresist, the chemically amplified photoresist comprising atleast a photo acid generator, a quencher and a salt having a bufferingfunction for an acid which is generated from said acid generator byirradiation; wherein: said salt having a buffering function for an acidwhich is generated from said acid generator comprises at least one saltselected from the group consisting of 4-n-dodecylphenylsulfonic acidtris(2-hydroxyethyl)amine, 3,5-dimethyl-4-(n-hexyloxy)phenylsulfonicacid-4-(2-acetoxyethyl)morpholine,5-isopropyl-2-methyl-4-(n-decyloxy)phenylsulfonic acidtris(2-isobutyryloxyethyl)amine, 4-n-dodecylphenylsulfonic acidtris(2-methoxymethoxyethyl)amine and2-methyl-4-(n-dodecyloxy)phenylsulfonic acid tris(2-acetoxyethyl)amine.20. A method of manufacturing a semiconductor integrated circuit deviceaccording to claim 19, wherein an irradiation for said exposure is madewith rays having a wavelength of at least 365 nm-0.1 nm or an electronbeam having an energy of 300 keV-1 keV.
 21. A method of manufacturing asemiconductor integrated circuit device according to claim 19, whereinsaid step of performing photolithography comprises the step of applyinga coating of the photoresist onto a via hole or a trench which is madein an insulating film formed on the substrate and exposing a partincluding said via hole or said trench.
 22. A method of manufacturing asemiconductor integrated circuit device according to claim 21, whereinsaid insulating film comprises at least one layer of alow-dielectric-constant film whose dielectric constant is not greaterthan
 3. 23. A method of manufacturing a semiconductor integrated circuitdevice according to claim 19, wherein, in said step of performingphotolithography, a thin film is formed on the substrate surface, andsaid thin film is a thin film including a nitrogen atom in constitutingatoms thereof.
 24. A method of manufacturing a semiconductor integratedcircuit device according to claim 23, wherein said nitrogen-containingthin film is one of TiN, SiN, SiCN and SiON films.